Abstract: This paper studies the flotation behavior of pyrite under the action of ultrasound.The results show that under the best conditions of flotation with a grinding fineness of-0.074 mm accounting for 57%, 200 g/t butyl xanthate, and 20 g/t foaming agent, the ultrasonic frequency is 135 kHz and the power is 100 W can increase the recovery rate of pyrite by 13.86%. The results of ultrasonic flotation and standard flotation showed that the high frequency ultrasonic treatment had the greatest influence on the flotation of pyrite of -150 μm+100 μm size fraction, and the recovery was improved by 7.54%. Five kinetic models are used to fit the experimental data of this particle size. The results show that the classical first-order flotation kinetic model gave excellent fits to the experimental data, and the description of kinetic equation is ultrasonic treatment flotation: ε=26.271-exp(-0.601 t), standard flotation: ε=18.011-exp(-0.671 t), respectively SEM analysis showed that the recovery of pyrite was improved mainly by the cleaning of surface.